 #include<iostream>
 #include<algorithm> 
 using namespace std;
 
 typedef long long ll;
 const int N =2e5+10;
 
ll n,c;
ll a[N];
ll ret=0;
int main()
{
	cin>>n>>c;
	
	for(int i=1;i<=n;i++)cin>>a[i];
	
	sort(a+1,a+1+n);
	
	for(int i=1;i<=n;i++)
	{
		ll b=a[i]-c;
		ret+=upper_bound(a+1,a+i,b)-lower_bound(a+1,a+i,b);
	}		
	cout<<ret<<endl;
	
	return 0;
}
